It's real name is MB-4 and it was (ans still is) the fastest midi system on the market, because the note was sensed by each fret that was divided in four section (5 on the fivers) and not by an hex pickup, even if there's one, it's only here for the effect (bend, dynamic,...) applied on the note played...
This is the first version as this infamous hex pickup was suppressed on the second one, the effect being sensed directly by the magnetic pickups.
It's a real piece of history.
For the module, the Peavey should work as they bought the rights for this system manufactured by the Australian Steve CHICK company.
More here : http://walbasshistory.blogspot.be/2014/06/wal-mb4-midi-bass.html